Specifications, Lock-in amplifiers – Atec Signal-Recovery-7280 User Manual
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CatIss7Web:0710UK
Specifications
General
Dual-phase DSP lock-in amplifier operating
over a reference frequency range of 0.5 Hz to
2.0 MHz. Direct digital demodulation using a
main ADC sampling rate of 7.5 MHz.
Wide range of extended measuring modes and
auxiliary inputs and outputs. User-upgradeable
firmware.
Measurement Modes
The instrument can simultaneously show any
four of these outputs on the front panel display:
X
In-phase
Y
Quadrature
R
Magnitude
θ
Phase Angle
Noise
Harmonic
nF, n
≤ 32
Dual Harmonic
Simultaneously measures the signal at
two different harmonics F
1
and F
2
of the
reference frequency
Dual Reference
Simultaneously measures the signal
at two different reference frequencies,
F
1
and F
2
where F
1
is the external and F
2
the internal reference
Frequency Ranges for Dual Harmonic and Dual
Reference Modes:
Standard Unit
F
1
and F
2
≤ 20 kHz
With option -/99
F
1
and F
2
≤ 800 kHz
With option -/98
F
1
and F
2
≤ 2.0 MHz
Virtual Reference
Locks to and detects a signal without a
reference (100 Hz
≤ F ≤ 2.0 MHz)
Noise
Measures noise in a given bandwidth
centered at the reference frequency F
Spectral Display
Gives a visual indication of the spectral
power distribution of the input signal in a
user-selected frequency range lying
between 1 Hz and 2.0 MHz. Note that
although the display is calibrated in terms
of frequency, it is not calibrated for
amplitude. Hence it is only intended to
assist in choosing the optimum reference
frequency
Display
320
× 240 pixel (¼ VGA)
electroluminescent panel giving digital,
analog bar-graph and graphical indication
of measured signals. Menu system with
dynamic key function allocation. On-
screen context sensitive help
Signal Channel
Voltage Input
Modes
A only, -B only or
Differential (A-B)
Full-scale Sensitivity
0.5 Hz
≤ F ≤ 250 kHz
10 nV to 1 V in a
1-2-5 sequence
250 kHz
< F ≤ 2.0 MHz 100 nV to 1 V in a
1-2-5 sequence
Max. Dynamic Reserve > 100 dB
Impedance
100 M
Ω // 25 pF
Maximum Safe Input
20 V pk-pk
Lock-in Amplifiers
Voltage Noise
5 nV/
√Hz @ 1 kHz
C.M.R.R.
> 100 dB @ 1 kHz
Frequency Response
0.5 Hz to 2.0 MHz
Gain Accuracy
±0.3% typ, ±0.6%
max. (full bandwidth)
Distortion
-90 dB THD (60 dB
AC gain, 1 kHz)
Line Filter
attenuates 50, 60,
100, 120 Hz
Grounding
BNC shields can be
grounded or floated
via 1 k
Ω to ground
Current Input
Mode
Low Noise, Normal or
Wide Bandwidth
Full-scale Sensitivity
Low Noise
10 fA to 10 nA in a
1-2-5 sequence
Normal
10 fA to 1 µA in a
1-2-5 sequence
Wide Bandwidth
F
≤ 250 kHz
1 pA to 100 µA in a
1-2-5 sequence
F > 250 kHz
10 pA to 100 µA in a
1-2-5 sequence
Max. Dynamic Reserve > 100 dB
Frequency Response (-3 dB)
Low Noise
≥ 500 Hz
Normal
≥ 50 kHz
Wide Bandwidth
≥ 1 MHz
Impedance
Low Noise
< 2.5 k
Ω @ 100 Hz
Normal
< 250
Ω @ 1 kHz
Wide Bandwidth
< 25
Ω @ 10 kHz
Noise
Low Noise
13 fA/
√Hz @ 500 Hz
Normal
130 fA/
√Hz @ 1 kHz
Wide Bandwidth
1.3 pA/
√Hz @ 1 kHz
Gain Accuracy
± 0.6% typ, midband
Line Filter
attenuates 50, 60,
100, 120 Hz
Grounding
BNC shield can be
grounded or floated
via 1 k
Ω to ground
Reference Channel
TTL Input (rear panel)
Frequency Range
0.5 Hz to 2.0 MHz
Analog Input (front panel)
Impedance
1 M
Ω // 30 pF
Sinusoidal Input
Level
1.0 V rms*
Frequency Range 0.5 Hz to 2.0 MHz
Squarewave Input
Level
250 mV rms*
Frequency Range
2 Hz to 2 MHz
*Note: Lower levels can be used with the
analog input at the expense of increased
phase errors
Phase Set Resolution
0.001
° increments
Phase Noise at 100 ms TC, 12 dB/octave slope
Internal Reference
< 0.0001
° rms
External Reference < 0.01
° rms @ 1 kHz
Orthogonality
90
° ±0.0001°
Acquisition Time
Internal Reference
instantaneous
acquisition
External Reference 2 cycles + 50 ms
Reference Frequency Meter Resolution
1 ppm or 1 mHz,
whichever is the
greater
Demodulator and Output Processing
Output Zero Stability
Digital Outputs
No zero drift on all
settings
Displays
No zero drift on all
settings
Analog Outputs
< 5 ppm/
°C
Harmonic Rejection
-90 dB
Output Filters
X, Y and R outputs only
Time Constant
1 µs to 1 ms in a 1-2-5
sequence, and 4 ms
Slope (roll-off)
6 and 12 dB/octave
All outputs
Time Constant
5 ms to 100 ks in a
1-2-5 sequence
Slope
6, 12, 18 and 24 dB/
octave
Synchronous Filter
Available for
F < 20 Hz
Offset
Auto and Manual on X
and/or Y: ±300% full-
scale
Absolute Phase Measurement Accuracy
≤ 0.01°
Oscillator
Frequency
Range
0.5 Hz to 2.0 MHz
Setting Resolution
1 mHz
Absolute Accuracy ± 50 ppm
Distortion (THD)
-80 dB @ 1 kHz and
100 mV rms
Amplitude (rms)
Range
1 mV to 1 V
Setting Resolution
1 mV
Accuracy
±0.2%
Stability
50 ppm/
°C
Output Impedance
50
Ω
Sweep
Amplitude Sweep
Output Range
0.000 to 1.000 V rms
Law
Linear
Step Rate
20 Hz maximum
(50 ms/step)
Frequency Sweep
Output Range
0.5 Hz to 2.0 MHz
Law
Linear or Logarithmic
Step Rate
20 Hz maximum
(50 ms/step)
Auxiliary Inputs
ADC 1, 2, 3 and 4
Maximum Input
±10 V
Resolution
1 mV
Accuracy
±20 mV
Input Impedance
1 M
Ω // 30 pF
Sample Rate
ADC 1 only
40 kHz max.
ADC 1 and 2
17.8 kHz max.
Trigger Mode
Internal, External or
burst
Trigger Input
TTL compatible